Hi @albertsaradin — great find! This is an interesting mismatch between the FHIR spec indicating that slicing is applicable to "an element that may occur more than once (e.g. in a list)" and the Smoking Status profile using a slice on an element with maximum cardinality of 1. We'll look into what it would take to support this nonstandard case

Quick follow up: I was able to step through our code and it looked to me like the valueCodeableConcept slice was actually being validated correctly. Was there a specific error you were seeing in your environment?

Separately, I think that the current version of the Smoking Status profile (STU7) is not well-defined. The relevant bits of the profile StructureDefinition are these three elements:

{
  "id" : "Observation.value[x]",
  "path" : "Observation.value[x]",
  "slicing" : {
    "discriminator" : [{
      "type" : "type",
      "path" : "$this"
    }],
    "ordered" : false,
    "rules" : "open"
  },
  "min" : 1,
  "max" : "1",
  "base" : {
    "path" : "Observation.value[x]",
    "min" : 0,
    "max" : "1"
  },
  "type" : [
    { "code" : "Quantity" },
    { "code" : "CodeableConcept" },
    { "code" : "string" },
    { "code" : "boolean" },
    { "code" : "integer" },
    { "code" : "Range" },
    { "code" : "Ratio" },
    { "code" : "SampledData" },
    { "code" : "time" },
    { "code" : "dateTime" },
    { "code" : "Period" }
  ]
}
{
  "id" : "Observation.value[x]:valueQuantity",
  "path" : "Observation.value[x]",
  "sliceName" : "valueQuantity",
  "min" : 0,
  "max" : "1",
  "base" : {
    "path" : "Observation.value[x]",
    "min" : 0,
    "max" : "1"
  },
  "type" : [{ "code" : "Quantity" }],
  "binding" : {
    "strength" : "required",
    "valueSet" : "http://terminology.hl7.org/ValueSet/v3-UnitsOfMeasureCaseSensitive"
  }
}
{
  "id" : "Observation.value[x]:valueCodeableConcept",
  "path" : "Observation.value[x]",
  "sliceName" : "valueCodeableConcept",
  "min" : 0,
  "max" : "1",
  "base" : {
    "path" : "Observation.value[x]",
    "min" : 0,
    "max" : "1"
  },
  "type" : [{ "code" : "CodeableConcept" }],
  "binding" : {
    "strength" : "extensible",
    "valueSet" : "http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113762.1.4.1267.3"
  }
}

While this looks like it should restrict the field to two specific types, I don't believe it will work as intended. The use of optional (minimum cardinality 0) slices without restricting ElementDefinition.type for value[x] actually means that all types are considered valid, and the required terminology binding is not strictly enforced. Internally we're using a modified version of this profile to work around the issue for now

Hi @mattwiller , Thank you for following up!

It throws error and doesn't validates when I try.

I attempted to debug the issue (though I'm not very experienced). The error I encountered is Expected array value for sliced element in packages/core/src/default-values.ts: 210.

      if (!Array.isArray(elementValue)) {
        throw new Error('Expected array value for sliced element');
      }

I used the latest medplum from the github.

Hi @mattwiller,

Thank you! You're fast man! I tried the code, and it works great.

However, there's a small UI problem. I'm not sure if we should create a separate issue or mention it here.

FYI, please go to the app:
app -> Resource Type: "Observation" -> "New..." -> Profiles -> "US Core Smoking Status Observation Profile"

The Value [CodeableConcept] should show the binding valueset, but unfortunately, it doesn't.

I hope that is also as easy to fix as this one!